System for cutting element position indication

ABSTRACT

Systems and methods for cutting element indication include an end effector having a jaw for clamping a material and a cutting element within the end effector and a processor. The cutting element is moveable relative to the end effector. The cutting element is driven by a drive element and a mechanism coupling the drive element to the cutting element. The processor is configured to determine a position of the cutting element relative to the end effector via a displacement of the drive element and a displacement of the mechanism and display, on a user interface, an indicator of the position of the cutting element relative to the end effector.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is continuation of U.S. patent application Ser.No. 16/253,612, filed Jan. 22, 2019 and entitled “System for MoveableElement Position Indication,” which is continuation of U.S. patentapplication Ser. No. 13/350,522, filed Jan. 13, 2012 and entitled“Indicator for Knife Location in a Stapling or Vessel SealingInstrument,” which claims the benefit of U.S. Provisional PatentApplication No. 61/443,115, filed Feb. 15, 2011 and entitled “Indicatorfor Knife Location in a Stapling or Vessel Sealing Instrument,” each ofwhich is incorporated herein by reference.

This application is related to the following applications: U.S.application Ser. No. 12/705,418, entitled “Cut and Seal Instrument”(Attorney Docket No. ISRG 02180/US), filed on Feb. 12, 2010; U.S.application Ser. No. 12/415,332 (Attorney Docket No. ISRG 01510/US),filed on Mar. 31, 2009; and U.S. application Ser. No. 11/478,531(Attorney Docket No. ISRG 0010/US), filed on Jun. 29, 2006, each ofwhich is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Minimally invasive surgeries performed by robotic surgical systems areknown and commonly used in clinical procedures where it is advantageousfor a human not to perform surgery directly. One example of such asystem is the minimally invasive robotic surgery system described incommonly owned U.S. Pat. No. 7,155,315, entitled “Camera ReferencedControl in a Minimally Invasive Surgical Apparatus.”

A common form of minimally invasive surgery is endoscopy. Endoscopicsurgical instruments in minimally invasive medical techniques generallyinclude an endoscope for viewing the surgical field, and working toolsdefining end effectors. Typical surgical end effectors include clamps,graspers, scissors, tissue cutters, staplers, or needle holders, asexamples. The working tools are similar to those used in conventional(open) surgery, except that the end effector of each tool is supportedon the end of, for example, an approximately 12-inch-long extensiontube. To manipulate end effectors, a human operator, typically asurgeon, manipulates or otherwise commands a master manipulator.Commands from the master manipulator are translated as appropriate, andsent to a slave manipulator. The slave manipulator then manipulates theend effectors according to the user's commands. As the surgeon issomewhat removed from the movement of the end effector, the surgeongenerally relies on feedback mechanisms, such as an endoscopic imaging,to determine the locations of the surgical tools within a patient'sbody. In general, in telesurgical systems, the surgeon is provided an“internal user interface.” This internal user interface includes adisplay that can be seen by the surgeon during the procedure.

Among the procedures performed in minimally invasive surgeries is theresection of tissue, which may include clamping, sealing and cutting ofa body tissue. In a tissue sealing and cutting procedure, the endeffector has mechanisms for sealing the tissue (e.g. RF energy, sutures,staples, etc.) and a cutting member (e.g. tissue cutter, blade, ablativeenergy). Typically, a sealing and cutting procedure involves the stepsof clamping a tissue, sealing the clamped tissue on either side of acutting line, then cutting the clamped tissue along the cutting line. Iffor any reason, the cutting process should stall or fail, this maypresent a hazard since the cutting member may remain in an exposedposition. Removal of the end effector with the cutting member in thisposition may result in inadvertent cutting of other tissues proximal ofthe device or may present a hazard to the surgeon or other surgicalstaff once the tool is removed. Since cutting failure is a lowoccurrence event, and the surgeon's view of the cutting element may beobscured by the end effector, a surgeon may not maintain an accuratemental model of how the cutting element is positioned and moved, and maybe unaware of the hazard presented by an exposed cutting element.

It would be desirable for systems and methods which provide indicationsand images that allow a physician to visualize and, more importantly, tohabitualize themselves with the position and location of the tissuecutter during a procedure. Such methods would enable physicians todevelop a intuitive “sense” for the how the tissue cutter operates so asto facilitate cutting and prevent potential tissue damage.

BRIEF SUMMARY OF THE INVENTION

Improved systems and methods for indicating a position of a tool of anend effector are provided. The claimed methods and systems relate todisplaying an image of a motor-driven tool clamping a material on a userinterface, the tool having a first and second jaw for clamping thematerial and a cutting element (e.g. a knife or blade) for cutting thematerial, and superimposing on the user interface display a visualindicator of a position of the cutting element. The cutting element(e.g. blade, knife) comprises various positions, wherein a positionrepresents a position and/or an orientation of the cutting element. Inmany embodiments, the tool comprises an end effector having a first andsecond jaw and a knife disposed within the end effector such that theknife moves along a longitudinal axis of the jaws from a pre-cutposition to a cut-complete position, thereby cutting the tissue clampedbetween the jaws. The knife positions may include any or all of: apre-cut position, a cut-complete position, a cut-incomplete position,and a exposed position. The described methods allow a user to visualizeor sense the location and/or orientation of the knife of the endeffector, even when the knife may not be visible due to interferencefrom the material or the jaws of the end effector, which is particularlyuseful in a minimally invasive robotic surgical procedure. The methodsand systems are advantageous as they allow surgeons to becomehabitualized with the movement of the knife during cutting, therebyimproving the surgeon's intuitive sense of the procedure. This isparticularly useful on the rare occasion when the movement of the knifeshould stall leaving the knife in an “exposed” or “cut-incomplete”position, which may potentially cause inadvertent tissue damage if thesurgeon is unaware of the hazard. While the various embodimentsdisclosed herein are primarily described with regard to surgicalapplications, these surgical applications are merely exampleapplications, and the disclosed end effectors, tools, and methods can beused in other suitable applications, both inside and outside a humanbody, as well as in non-surgical applications.

In a preferred embodiment, an indication of knife position issuperimposed on the display during and/or after a cutting procedure, andmore preferably at all times during the procedure. The indication maycomprise any visual indicator sufficient to communicate the position ofthe knife to a user. The knife position may further include the locationof the knife on the end effector and/or an orientation of the knife.Ideally, the indicator of knife position includes a syntheticrepresentation of the knife superimposed on the image of the endeffector at a location corresponding to the actual knife location andorientation on the end effector.

In an embodiment, the method includes tracking a moveable element in anenvironment, wherein at least a portion of the element is hidden fromview in an image of the environment displayed on a user interface duringa procedure and displaying on the user interface an indicator of aposition of the element. The portion of the element hidden from view maybe visible at other times during the procedure. Additionally, theportion of the element which is hidden from view may change during theprocedure, such as when the element is moved through the environment orwhen tissue or other tool components visible in the environment moverelative to the element. Tracking the element may include determining alocation or an orientation of the element, often determined relative toa tool moveably coupled to the element. In many embodiments, the elementcomprises a cutting blade for cutting a body tissue of a patient coupledto the tool which is inserted into a body cavity of a patient, such asin a minimally invasive surgical procedure. Tracking the element mayinclude tracking a mechanism moving the element or processing images ofpositional markers disposed on the element. The indicator of theposition of the element may be displayed on the user interface so as tohabitualize a user to the position as the element moves between aplurality of positions. In some embodiments, the indicator of positionmay provide an alternate indication in response to a trigger condition,such as an indication that the element has stopped when the elementunexpectedly stops between a first and second position. Displaying theindicator on the user interface may include displaying a representationof the element on the display, such as a synthetic representation of theelement on a video image of the environment and/or the tool. Preferably,the indicator of position is dynamic such that the indicator conveys themotion of the element allowing the user to see and become accustomed tothe movement of the element during a procedure.

In many embodiments, the methods and systems include clamping the tissuebetween a first and second jaw of the tool, and energizing a motor ofthe tool in response to a user command to clamp the tissue, the motorbeing operatively coupled to the knife so as to move the knife relativeto the jaws between a pre-cut knife position and a cut-complete knifeposition, thereby cutting the tissue. Since the knife is typicallydisposed at least partially between the jaws, the jaws of the tool mayinhibit viewing of the moving knife in an image of the tool during theprocedure. Typically, the clamping and cutting occur in response to auser command to cut or clamp, however, cutting may also occurautomatically after successful clamping. Typically, the tissue isclamped, then sealed on either side of a cutting line before cutting thetissue along the cutting line.

In an embodiment, the methods and system may include superimposing awarning indication of a knife position on the user interface duringand/or after the cutting procedure, such as when the movement of theknife stalls leaving the knife exposed. The warning may be a separateindication from the above described indication of knife position so asto notify a user of a hazardous condition that may be caused by a stallor failure in cutting. For example, the display may include a warninglight that lights when the knife is stalled or exposed in response tothe knife stalling during the cutting procedure.

In an embodiment, the system includes a moveable element, a userinterface display and a processor coupling the element to the userinterface display so that the processor can output a visual indicator ofa position of the element on the display. In many embodiments, thesystem further includes a tool moveably coupled to the element and animage capturing device, such as a video camera. The processor and/or theimage capture device may be used to measure the location or orientationof the element relative to the tool or vice versa. The element is oftenmoveable between a plurality of positions on the tool, preferably afirst and second position. In many embodiments, the system processespositional information obtained by the processor (e.g. images from animage capture device) to determine the relative positions of the elementand tool. The processor may be coupled to a mechanism effecting movementof the element so that the position of the element or the tool can bedetermined by the processor from a displacement of the mechanism.

In many embodiments, the tool includes an end effector having jaws forclamping a material and a cutting element (e.g. a knife or blade) forcutting the clamped material. Typically, the tool is a surgical toolhaving jaws for clamping tissue and a knife for cutting the clampedtissue. The knife is configured to move between the jaws from a pre-cutposition to a cut-complete position, thereby cutting tissue clampedbetween the jaws. In the pre-cut and cut-complete position, a cuttingedge of the knife is disposed safely in the end effector so as toprotect adjacent tissue. The knife may include additional knifepositions between the pre-cut and cut-complete position, including butnot limited to a “knife-exposed” position and a “cut-incomplete”position. A knife position may further include the position and/ororientation of the knife relative to the end effector.

In many embodiments, the user interface display is coupled with theprocessor and image capture device so as to display an image of the endeffector of the tool and an indication of knife position. If for anyreason the tool is not visible, the user will be able to view anindicator of location and representation of the knife superimposed on animage of the tool. In a preferred embodiment, the indicator of knifeposition includes a synthetic representation of the knife superimposedon an image, actual or synthetic, of the end effector. The display mayalso indicate a warning separate from the indicator of knife positionthat the knife has stalled and presents a hazard, such as a stalledconfiguration or an exposed cutting edge of the knife.

For a fuller understanding of the nature and advantages of the presentinvention, reference should be made to the ensuing detailed descriptionand accompanying drawings. Other aspects, objects and advantages of theinvention will be apparent from the drawings and detailed descriptionthat follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top view of an operating room which includes a minimallyinvasive telesurgical system in accordance with many embodiments;

FIG. 2 is a front view of a patient cart for the minimally invasivetelesurgical system of FIG. 1;

FIG. 3 is a block diagram representing components of the minimallyinvasive telesurgical system of FIG. 1;

FIG. 4 is a diagrammatic view of a cut and seal surgical tool, inaccordance with many embodiments;

FIG. 5 is a diagrammatic top view of a removable cut and seal cartridgeof a surgical tool, in accordance with many embodiments;

FIG. 6 is a perspective view of the distal end of a combined cut andseal minimally invasive surgical instrument, in accordance with manyembodiments;

FIG. 7 is a side cross-sectional view of the embodiment of FIG. 6showing different positions of the knife, in accordance with manyembodiments;

FIG. 8 is a diagrammatic view of a surgical tool, in accordance withmany embodiments;

FIG. 9 is a diagrammatic view of a system, in accordance with manyembodiments;

FIG. 10 illustrates a user interface display showing images of the toolwith an indicator of knife position, in accordance with manyembodiments;

FIG. 11 is a diagrammatic view that illustrates a combined tissuecutting and sealing system using tool tracking, in accordance with manyembodiments; and

FIGS. 12-13 is a diagrammatic representation of methods, in accordancewith many embodiments; and

DETAILED DESCRIPTION OF THE INVENTION

In the following description, various embodiments of the presentinvention will be described. For purposes of explanation, specificconfigurations and details are set forth in order to provide a morethorough understanding of the embodiments. However, it will also beapparent to one skilled in the art that the present invention may bepracticed without the specific details. Furthermore, well-known featuresmay be omitted or simplified in order not to obscure the embodimentbeing described.

Improved systems and methods for indicating a location and/or anorientation of a cutting element on a tool during a cutting procedureare provided. The claimed methods and systems may be used in conjunctionwith other methods of tracking so as to allow a user to perceive aposition or orientation of the cutting element relative to the tool.These methods and systems are usefully in robotic systems where a usermay not be able to see the cutting element during cutting, which isparticularly useful in minimally invasive surgical procedures using amotor-driven end effector. These methods are advantageous as they allowa surgeon, removed from the end effector, to develop a sense of how thecutting member moves in relation to the tool during the procedure. Bycreating a sensory indication of a position of the cutting memberrelative to the tool, the methods allow a surgeon to become accustomedto the location of the cutting member on the tool, such that, should thecutting procedure fail, the surgeon would be aware of a potential hazardpresented by the cutting member and can take appropriate action to avoidthe hazard. While the various embodiments disclosed herein are primarilydescribed with regard to surgical applications, these surgicalapplications are merely example applications, and the disclosed endeffectors, tools, and methods can be used in other suitableapplications, both inside and outside a human body, as well as innon-surgical applications.

Referring now to the drawings, in which like reference numeralsrepresent like parts throughout several views, FIG. 1 shows a minimallyinvasive telesurgical system 1 having an operator station or surgeonconsole 3 in accordance with many embodiments. The surgeon console 3includes a display 15 where an image of a surgical site is displayed toa surgeon S. As is known, a support (not shown) is provided on which thesurgeon S can rest his or her forearms while gripping two mastercontrols, one in each hand. Although more controls may be provided ifmore end effectors are available, typically a surgeon manipulates onlytwo controls at a time; if multiple end effectors are used, the surgeonreleases one end effector with a master control and grasps another withsame master control. When using surgeon console 3, the surgeon Stypically sits in a chair in front of the surgeon console, positions hisor her eyes in front of the display 5, and grips the master controls,one in each hand, while resting his or her forearms on the support.

A patient side cart 5 of the telesurgical system 1 is positionedadjacent to a patient P. In use, the patient side cart 5 is positionedclose to the patient P requiring surgery. The patient side cart 5typically is stationary during a surgical procedure and includes roboticassemblies 5A, 5B, 5C, and 5D. The surgeon console 3 is typicallypositioned remote from the patient side cart 5 and may be separated fromthe patient side cart by a great distance, even miles away, but willtypically be used within the same operating room as the patient cart.Each of the robotic arm assemblies 5A, 5B, and 5C includes a surgicalinstrument or tool 7A, 7B, and 7C, respectively. Assembly 5D may includean endoscope for imaging the tool on the display during the procedure.The tools 7A, 7B, and 7C of the robotic arm assemblies 5A, 5B, and 5Cinclude end effectors 9A, 9B, and 9C, respectively. Movement of the endeffectors 9A, 9B, and 9C relative to the ends of the shafts of the tools7A, 7B, and 7C is also controlled by the master controls of the surgeonconsole 3. Any of tools 7A, 7B, and 7C may include a tissue cutting andsealing instrument. Such an instrument may comprise an end effectorhaving jaws for clamping a tissue, a member for sealing the tissue(e.g., a stapling or RF mechanism), and a member for cutting the tissueafter sealing (e.g., a movable blade, a knife, or any tissue cuttingmechanism), an example of which is illustrated in FIGS. 4-7. FIG. 2shows a front view of patient cart and the associated robotic armassemblies.

The telesurgical system 1 includes a vision cart 11. In an embodiment,the vision cart 11 includes most of the computer equipment or othercontrols for operating the telesurgical system 1. As an example, signalssent by the master controllers of the surgeon console 30 may be sent tothe vision cart 11, which in turn may interpret the signals and generatecommands for the end effectors 9A, 9B, 9C and/or robotic arm assemblies5A, 5B, 5C. In addition, video sent from an the image capturing device5D, such as an endoscope, to the display 15 may be processed by, orsimply transferred by, the vision cart 11.

FIG. 3 is a diagrammatic representation of the telesurgical system 1. Ascan be seen, the system includes the surgeon console 3, the patient sidecart 5, and the vision cart 11. In addition, in accordance with anembodiment, an additional computer 13 and display 15 are provided. Thesecomponents may be incorporated in one or more of the surgeon console 3,the patient side cart 5, and/or the vision cart 11. For example, thefeatures of the computer 82 may be incorporated into the vision cart 11.In addition, the features of the display 15 may be incorporated into thesurgeon console 3, for example, in the display 5, or maybe provided by acompletely separate display or the surgeon console or on anotherlocation. In addition, in accordance with an embodiment, the computer 13may generate information that may be utilized without a display, such asthe display 15.

FIG. 4 is a diagrammatic view of an exemplary cut and seal surgicalinstrument 2 in accordance with an aspect of the invention. As shown inFIG. 4, instrument 2 includes a force transmission mechanism 4 at theproximal end (outside the patient) and a combined cut and seal endeffector 6 at the distal end (inside the patient; closer to the surgicalsite). Transmission mechanism 4 and cut and seal end effector 6 arecoupled by instrument shaft 8. Cut and seal end effector 6 is optionallycoupled to instrument shaft 8 via wrist mechanism 10. Instrument 2 istypically used to carry out minimally invasive surgery, during which endeffector 6 and a distal part of shaft 8 are inserted into a patient viaa small incision or natural orifice, typically through a cannula, tocarry out a surgical procedure.

In the depicted embodiment, force transmission mechanism 4 includesdisks 12, which mate to corresponding servomotors (not shown) wheninstrument 2 is mounted, e.g., for use in a surgical robotic system. Theservomotors provide actuating forces to move components of instrument 2.Four disks 12 are shown; however, more or fewer may be used, dependingon the desired actuated degrees of freedom for instrument 2. Theservomotors are controlled by a surgeon moving a master manipulator, asdescribed in more detail below. In addition, one or more servomotors 14,16 may be mounted on instrument 2 itself to provide actuating forces forinstrument 2 components. Shaft 8 is generally a hollow tube throughwhich actuating cables run from transmission mechanism 4 to thecomponents at the distal end of instrument 2. Such cables areillustrative of various ways (e.g., rods, rotating shafts, and the like)of moving instrument components. In some embodiments, shaft 8 rotates toprovide roll to end effector 6. Shaft 8, and end effector 6, may havevarious outer diameters (e.g., 5 mm, 8 mm, 10 mm, 12 mm, etc.). Althoughshaft 8 is depicted as rigid, it is also illustrative of variousflexible embodiments that may be used.

In the embodiment depicted in FIG. 4, cut and seal end effector 6includes a stationary jaw member 18, a movable jaw member 20, and aremovable cut and seal cartridge 22 that is removably coupled tostationary jaw member 18. Tissue is clamped between jaws 18 and 20 forcutting and sealing. Cut and seal cartridge 22 includes a movable knife24 (e.g., a sharp blade or tissue cutter). Movable jaw member 20 may beactuated via a force transmitted through force transmission mechanism 4,or it may be actuated by one of the motors 14, 16 mounted on instrument2. Similarly, knife 24 may be actuated via a force transmitted throughforce transmission mechanism 4 or by one of the motors 14, 16. In oneaspect, a single motor 14 or 16 may be used to actuate both jaw 20 andknife 24. In one alternate aspect, jaw 18 may be movable and jaw 20stationary, such that cartridge 22 is moved during instrument operation.In another alternate aspect, both jaws 18 and 20 are moveable.

End effector 6 also includes tissue sealing capability. A first tissuesealing electrode 26 is positioned on the inner face of cartridge 22. Asecond tissue sealing electrode 28 is positioned on jaw 20, opposingelectrode 26. Electrodes 26, 28 are described in more detail below.Electrical energy for tissue sealing is provided to electrodes 26, 28via an electrical coupling 30 at the proximal end of instrument 2.Electrical coupling 30 as depicted in FIG. 4 is illustrative of variouspositions at which it may be placed on the instrument, and it mayrequire manual coupling to a tissue sealing energy source or it maycouple automatically to the energy source when instrument 2 is mountedto a robotic manipulator for surgical operation. Alternatively, tissuesealing capability may be provided by other means, such as by staplingor suturing, which may be performed by the end effector.

FIG. 5 is a diagrammatic top view of removable cut and seal cartridge22. Electrode 26 is depicted in an elongated “U” shape so that itsurrounds a slot 32 through which knife 24 moves. Various otherelectrode shapes or configurations may be used. In many aspectselectrode 26 is positioned on both sides of slot 32 so that both freeends of a cut tissue (e.g., a blood vessel) are sealed before the tissueis cut between the two seals. FIG. 5 also shows that knife 24 is mountedon a sled 34 that moves as lead screw 36 rotates. Lead screw 36 isattached to a mechanical coupling 38 at the proximal end of cartridge22, and coupling 38 attaches to a drive shaft when cartridge 22 isinstalled in instrument 2. Details of the coupling are described below.As described herein, knife 24 moves proximally to cut tissue. It is wellunderstood, however, that knife 24 may move distally to perform itscutting action using a similar sled and lead screw operating mechanism.

FIG. 5 also shows that in some aspects cartridge 22 includes anelectronic encryption device 42 (e.g., integrated circuit with datastorage capability; in practice this is sometimes referred to as a“Dallas chip”). Electronic encryption device 42 may be used to conveyinformation to the cut and seal control system (see below) about thecartridge type, if the cartridge has been used (to enforce one-time userestrictions), or the number of available lives for use (to managemultiple use restrictions (e.g., three uses)). Electronic encryptiondevice 42 may also be used to ensure that a properly manufacturedcartridge is being used. Electrical coupling 43 provides a connectionpoint for encryption device 42. FIG. 5 also shows two snap fittings 44,which are illustrative of various ways of securely yet removablyfastening removable cut and seal cartridge 22 in instrument 2.

FIG. 6 is a perspective view of an embodiment of the distal end of acombined cut and seal minimally invasive surgical tool, generallydescribed above as end effector 6, in accordance with many embodiments.FIG. 6 shows stationary jaw member 50 coupled to instrument shaft 52(the optional wrist mechanism is omitted for clarity). A channel 54 injaw member 50 receives removable cut and seal cartridge 56. Matchingguide rails 57 and grooves (not shown) may be used in channel 54 and oncut and seal cartridge 56 to improve alignment and secure mounting. Anillustrative electrical coupling 58 for cut and seal cartridge 56 isshown at the proximal end of channel 54 (in this perspective view, themechanical and other electrical couplings are hidden). As cartridge 56is secured in position within channel 54, the necessary electrical andmechanical couplings are automatically made.

As shown in FIG. 6, cut and seal cartridge 56 includes a tissue sealingelectrode 60 that receives electrical tissue sealing energy via theelectrical coupling in channel 54. A slot 62 in electrode 60 allows aknife (not shown) to rise above electrode 60's surface and moveproximally (or distally) to cut tissue clamped between the jaw members.A raised tab 64 at the proximal end of cartridge 56 provides additionalcontact area for electrical connections, as well as a safety positionfor the tissue cutter, as described below. Fittings 66 (one is hidden)hold cartridge 56 in place in corresponding detents 68 in jaw member 50.Alternatively, cartridge 56 may also include a stapling mechanism forsealing the tissue prior to cutting. As can be appreciated from FIG. 6,the movement of the knife would not be visible to an endoscope or to asurgeon when moving within a clamped end effector. Movable jaw member 70is coupled at hinge 72. Tissue sealing electrode 74 is shaped andpositioned on jaw member 70 so that it is aligned with cut and sealcartridge electrode 60 when the cartridge is secured in channel 54.Electrode 74, and jaw member 70, includes a slot (not shown) to allowthe tissue cutter in cartridge 56 to extend into jaw member 70 duringcutting operations.

FIG. 7 is a side cross-sectional view of the end effector embodimentdepicted in FIG. 6, with the cut and seal cartridge securely positionedin the stationary jaw member. The embodiment shown in FIG. 7 isillustrative of working aspects of the distal end of the combined cutand seal end effector. As shown in FIG. 7, a first lead screw 78operates movable jaw member 70. As lead screw 78 rotates (e.g., actuatedby one of the motors 14, 16), a sliding member travels proximally movingjaw member 70 towards jaw member 50 to clamp tissue in between them. Theuse of the lead screw provides the strong clamping force sufficient foreffective tissue sealing and cutting. When the tissue is clamped withsufficient force (clamping force feedback or other feedback may beused), the sealing and cutting operations may begin. During sealing,electrodes 60 and 74 receive electrical sealing energy to seal theclamped tissue. When sealing is complete, tissue cutting may begin.

A second lead screw 82 inside cut and seal cartridge 56 operates knife84 having cutting edge 85 for cutting tissue. Knife 84 may comprise anymember having a cutting edge sufficient to cut tissue. As lead screw 82rotates, sled 86 moves knife 84 (i.e., a sharp blade) proximally fromPosition A to Position C to cut tissue clamped between the jaw members.As knife 84 starts to move, it engages tab 88, which causes knife 84 torotate around hinge 90 and extend beyond the clamping surfaces ofelectrodes 60 and 74. Other ways of keeping the tissue cutting bladesafe include, for example, surrounding it in a small raised coveringwhen not in use. Tab 64 provides a safety position for knife 84 after itmoves to its proximal position at Position C. In some aspects, afterknife 84 has cut tissue, lead screw 82 may be rotated in the oppositedirection to return knife 84 to its distal, ready to cut position. Inthis way, the cutting feature of removable cut and seal cartridge 56 maybe reused, so that both the cutting and sealing operations may beperformed more than once with a single cartridge. Such multiple use hasa significant cost saving benefit.

Lead screw 82 is coupled to receive mechanical power (e.g., from one ofmotors 14, 16 (see FIG. 1)) via mechanical coupling 92. Mechanicalcoupling 92 includes a spring 94 that forces the coupling distally. Whenseal cartridge 56 is first fully inserted into jaw member 50, the matingmechanical couplings on the cartridge and in the jaw member may not bealigned (e.g., splines or various shapes may not be aligned). The forceprovided by spring 94 will move the instrument side coupling to fullyengage the cartridge coupling as soon as it rotates into properalignment.

FIG. 7 also illustrates three different positions of the knife, PositionA, Position B, and Position C. In the current embodiment, knife 84 cutsas it moves proximally from Position A to Position C (as indicated bythe arrows). As shown, the lead screw 82 actuates movement of the knife84 along a longitudinal axis of the end effector. Although FIG. 7depicts knife at the distal end of its path in Position A, during thecutting procedure knife 84 would move through various other positions,including Positions B and C (shown in dotted lines). In Position A,knife 84 is safely disposed within the distal portion of the cartridge.In position B, the knife has rotated around hinge 90 and travelledmid-way along its cutting path, its cutting edge 85 extending above thecartridge so as to cut tissue clamped within its path. In Position C,knife 84 is at the proximal end of its cutting path and is safelydisposed in a proximal portion of the end effector, its cutting edgecovered by tab 64. Tissue cutter 84 has a cutting edge 85 facing towardthe proximal end of the end effector, such that knife 84 cuts clampedtissue when actuated to move from Position A to Position C. In analternative embodiment, the cutting edge 85 may be disposed on knife 84facing toward a distal portion of the end effector, such that the knife84 would cut tissue when actuated to move distally from Position C toPosition A. In some embodiments knife 84 may include a cutting edgefacing in both directions, such that moving knife 84 in either directionwould cut tissue clamped within the end effector.

In many embodiments, knife 84 includes a number of “positions” and mayinclude positions other than those described in FIG. 7. For example, inan embodiment having a knife 84 that cuts tissue when moving distally,the knife may include a pre-cut position at Position C and acut-complete position at Position A. Knife 84 may also includeadditional positions, such as any intermediate position betweenPositions A and C (e.g. Position B). Any such positions may be termed a“cut-incomplete position,” since the knife 84 would have cut tissuealong only part of the cutting path. The “knife positions” may alsocomprise an orientation of the knife. For example, Position B, as wellas any position between A and C may be considered a “knife-exposed”position, indicating that the cutting edge 85 of knife 84 is exposed soas to cut tissue.

As can be see in FIG. 7, if for any reason, knife 84 were to stallduring the cutting procedure, knife 84 would remain in a positionbetween Position A and Position C, such as in Position B. If stalled inPosition B, the cutting edge 85 of knife 84 would remain exposed, andsubsequent movement of the knife 84 could potentially result ininadvertent cutting of tissue as the tool is withdrawn. Additionally,once the end effector was removed, if the surgeon was unaware that thecutting edge 85 was exposed, the cutting edge 85 could cut the hand ofthe surgeon, potentially exposing the surgeon to biological hazards.Such hazards might be avoided, however, through use of the claimedmethods and systems.

In many embodiments, the tissue cutting and sealing systems describedabove are implemented in a minimally invasive surgical robotic system(e.g., a da Vinci® Surgical System). Typically, to carry out aprocedure, the surgeon first moves an end effector of a surgicalinstrument into position at a surgical site and clamps tissue (e.g., ablood vessel) to be sealed and cut. Ideally, in order to achieve aneffective tissue seal, the tissue should be clamped between the surgicalinstrument's electrodes with sufficient force (e.g., in the range of100-150 psi). When the proper clamping force is achieved (automaticallyor under the surgeon's control), the surgeon commands the sealingoperation which may include sending a signal to an electro-sealing unitor applying a force to fire a staple. When sealing is complete, thesystem may automatically generate a signal to the tool to begin thecutting operation without a separate cut command from the surgeon. Thus,combined cutting and sealing is carried out with a single command fromthe surgeon as the cut and seal controller controls both cutting andsealing aspects of the end effector. In additional aspects of theinvention, a cut and seal controller may automatically send a signal tothe end effector to either loosen or release the clamping force or mayautomatically send a signal to the end effector to reset the knife inpreparation for another combined cut and seal actuation. The cut andseal controller may also command various combinations or all of theseautomatic actions in response to a single command signal from thesurgeon. Further, the cut and seal controller may issue updatedinformation to the electronic encryption device in instrument toeffectively manage use restrictions, as described above.

FIG. 8 schematically illustrates a robotic tool 180 in accordance withan embodiment of the present invention. The robotic tool 180 includes aclamp manipulator 196 with a first drive 198, a knife controller 182with a second drive 184, a processor 191, a PSM 193, and an end effector188. End effector 188 is coupled with the first and second drive throughinstrument shaft 186. Instrument shaft includes a first mechanism 190operatively coupling first drive 198 with an opposable jaw 194 of endeffector 188, such that when actuated opposable jaw 194 clamps a tissue.Instrument shaft further includes a second mechanism 192 operativelycoupling second drive 184 with knife 195, such that, when actuated,knife 195 moves along a longitudinal axis of the jaws of the clampcutting the clamped tissue. The clamp manipulator and knife are alsocoupled with a processor 191 and the surgeon's console. The processor191 may determine a position of the end effector 188, jaw 194 of the endeffector and knife 195 from positional information obtained by the PSM193 (e.g. by tracking the kinematic chain). Once the positional data foreach component is determined, processor 191 may send an output of theimage of the tool and a visual indicator of a position of the knife tothe display. As discussed above, the position of the knife may includean indication of a position and/or orientation of the knife 195 relativeto end effector 188. The various positions may include but are notlimited to a pre-cut position, a cut-complete position, a cut-incompleteposition, and an exposed position, as discussed previously. Processor191 may also determine the positions of the jaw 194 or the knife 195from the displacement of the first or second mechanism 190, 192 or themotor displacement of the first drive 198 or second drive 184.

FIG. 9 is a diagrammatic view of a telerobotic surgical system inaccordance with many embodiments. In the example of FIG. 9, a physicianinputs a command to the system to clamp or cut a tissue. In response tothe user command, the system begins driving motor 210 to drive clampingby actuating the jaws or to drive cutting of the tissue by moving theknife with mechanism 240. As mechanism 240 effects clamping or cutting,processor 220 receives positional information (or derivatives thereof)from sensor 230. The positional information may be derived from thedisplacement of the mechanism or motor, as described previously, or mayobtained directly by the sensor 230, such as through detection offiducial markers disposed on the jaws and/or knife. For example,positional markers may be placed on the jaws of the end effector and onthe knife such that a sensor, such as an image capture device, can trackmovement of the knife relative to the end effector. The position of theelement (e.g., knife) may also be tracked by a sensor 230 which isdisposed on or near the element, such as by one or more electromagneticposition sensors or pressure sensitive sensors. Additionally, a greenoptical fiber may be incorporated into the knife mechanism to allowvisualization of the knife location through detection of light emittedthrough the fiber. More information regarding the use of fiducialmarkers, as may be used in many embodiments of the present invention,can be found in commonly-owned U.S. application Ser. No. 12/428,657(Attorney Docket No. ISRG 01480/US) entitled “Fiducial Marker Design andDetection for Locating Surgical Instrument in Images,” filed on Apr. 23,2009), the entirety of which is hereby incorporated by reference. Oncethe relative positions and/or configuration of the knife (also known asthe knife position) have been determined, processor 220 outputs a visualindicator 250 of the knife position to be superimposed on the display 15with an image of the end effector. Typically, display 15 includes imagesof the end effector and the visual indicator of knife position issuperimposed on the display during cutting, and more preferably at alltimes during the procedure, such that the surgeon becomes accustomed toor habitualized with the position and movement of the knife during thecutting process.

FIG. 10 illustrates three examples of visual indicator 250 showing aknife position on display 15, in accordance with an embodiment whereinthe knife cuts tissue as it moves distally along the tool. The indicatorof knife position is superimposed on the user interface display 15,which also display images and/or visual representations of the surgicaltool end effectors during the cutting procedure. Indicator 250 may beany indicator (e.g. a light, text message, color change on display,etc.) sufficient to indicate a knife position to a user. Indicator 250may include a synthetic representation 252 of the knife superimposedover either a synthetic representation or over an actual image of thetool shown on display 15. FIG. 10 shows three consecutive images of theend effector 189 on display 15 during a tissue cutting procedure inFrames I, II and III. In Frame I, the knife is in the pre-cut positiondisposed safely in the proximal portion of end effector 189, whileindicator 250 shows the knife position as “Pre-Cut” and shows asynthetic representation 252 of the knife on the end effector. In FrameII, the knife has moved mid-way along the jaws of the end effector withthe cutting edge of the knife exposed so as to cut tissue when moveddistally. Indicator 250 shows a knife position indicator as “Knife:Exposed!” and the synthetic representation 252 midway along the tool. Iffor any reason, the knife should fail or stall as it moves from itspre-cut position to its cut-complete position, an optional warning maybe output on the display. The warning may indicate the knife position asbeing “cut-incomplete,” “exposed,” or “stalled” (not shown). In FrameIII, the knife has successfully moved the jaws of end effector 189 toits cut-complete position and has rotated so as to be safely disposedwithin the distal portion of end effector 189. Indicator 250 shows theknife position as “Cut-Complete” and the synthetic representation 252depicting the location and orientation of the knife at its distal mostposition on end effector 189.

Knife Position Indicator with Tool Tracking

In some embodiments, the methods and systems may include tool tracking.In tool tracking a positional component is included in or is otherwiseassociated with the computer. The positional component providesinformation about a position of a tool, such as end effector 189, or anelement, such as the knife. “Position” refers to at least one of thelocation and/or the orientation of the end effector. The position can bedetermined through the use of fiduciary markers, configuration markersor by tracking of the kinematic chain. A variety of differenttechnologies, which may or may not be considered tool tracking devices,may be used to provide information about a position of an end effector.In a simple embodiment, the positional component utilizes a video feedfrom an image capturing device to provide information about the positionof an end effector and/or the knife; however, other information may beused instead of, or in addition to, this visual information, includingsensor information, kinematic information, or any combination thereof.Examples of systems that may be used for the tool tracking component aredisclosed in U.S. Application Publication No. 2006/0258938, entitled,“Methods and System for Performing 3-D Tool Tracking by Fusion of Sensorand/or Camera Derived Data During Minimally Invasive Robotic Surgery”;U.S. Pat. No. 5,950,629, entitled “System for Assisting a Surgeon DuringSurgery”; U.S. Pat. No. 6,468,265, entitled “Performing Cardiac SurgeryWithout Cardioplegia”; and U.S. Application Publication No.2008/0004603, entitled “Tool Position and Identification IndicatorDisplayed in a Boundary Area of a Computer Display Screen.” The tooltracking component may utilize the systems and methods described incommonly owned U.S. application Ser. No. 12/428,657 (Attorney Docket No.ISRG 01480/US), entitled “Fiducial Marker Design And Detection ForLocating Surgical Instrument In Images” and U.S. application Ser. No.12/428,691 (Attorney Docket No. ISRG 01910/US), entitled “ConfigurationMarker Design and Detection for Instrument Tracking”. In general, thepositional component conveys information about the actual position andorientation of en end effector. This information is updated dependingupon when the information is available, and may be, for example,asynchronous information.

Synthetic Knife Image at Actual Location of End Effector

In accordance with another embodiment, the synthetic knife image may bedisplayed over the actual location of a knife. This feature permits asurgeon S to follow the knife even when the knife is out of sight, forexample when the knife is behind an organ or is covered by blood, suchis often the case with the knife in a sealing and cutting instrument.Since the knife moves along the jaws of the end effector when the jawsare clamped on tissue, the knife is typically not visible with anendoscope as it is obscured by the jaws and/or the clamped tissue.

In accordance with an embodiment, the synthetic representation of theknife may be a two or three-dimensional model of the knife, and may beoriented so as to be consistent with the actual orientation of the kniferelative to the tool. Thus, by using the claimed system and methods, thesurgeon S would be aware of the position of the knife relative to theend effector throughout a procedure, which is particularly useful shouldthe procedure stall or fail.

FIG. 11 is a flowchart showing steps for displaying a synthetic knife atthe actual location of knife in accordance with many embodiments.Beginning at step 1100, the knife is in a first position. At step 1102,the synthetic representation of the knife is displayed over the image ofthe actual tool, which may be, for example, live video of the endeffector tool. At step 1104, the knife moves to position B. Typically,the knife moves through position B on its way to a final position C(known as the cut-complete position). Kinematic position information isreceived at step 1106, and an adjustment for offset is taken in step1108. At step 1109 if the end effector tool or knife is not visible froman endoscope, a synthetic image is displayed. Although typically, theend effector tool remains in the first position during the cuttingprocess, if for any reason the tool moves, a similar tool trackingprocess optionally can be used to track the movement of the tool anddisplay a synthetic representation of the end effector should the endeffector tool no longer be visible. Since in its usual operation, theknife is obscured by the jaws of the end effector, the system willtypically display the synthetic image of the knife tool. Thus, thesynthetic image of the knife may be displayed on either an actual imageof the end effector or on a synthetic image of the end effector,depending on whether the end effector is visible at any given time. Atstep 1110, the synthetic knife is displayed at the kinematicallyadjusted position of the tool. Thus, in accordance with the abovedescribed methods, the synthetic knife image is displayed on the imageof the end effector, indicating the knife position of the knife duringthe cutting of tissue, and preferably at all times during cutting of thetissue.

Utilizing the method of FIG. 11, the movements of the synthetic knifematches the movements of the actual knife. Preferably, the movement ofthe synthetic knife is updated in real time so that the movement of thesynthetic knife closely matches the movement of the actual tool so as toconvey movement of the knife. As described above, although kineticposition information typically does not provide an accurate position ofa knife in space, a change in position is relatively accurate. Thus, byutilizing the synthetic knife described with reference to FIG. 11, theposition of the knife, can be followed fairly accurately, even whenvideo or other position information for the tool is lost. As withprevious embodiments, this synthetic representation of the knife for usein the method of FIG. 11 may be a three-dimensional model of the knife,or may be a line drawing of the knife or broken lines representingportions of the knife, or any other representation of the knife.

FIGS. 12-13 illustrate methods in accordance with many embodiments.Method 300, shown in FIG. 12, includes a step 301 of displaying an imageon a user interface display of a tool clamping a body tissue and a step302 of superimposing a visual indicator of knife position on the displayduring and/or after cutting of the clamped tissue with the knife. Method310, shown in FIG. 13, includes a step 312 of clamping tissue with thejaws of a tool in response to a user command to clamp, a step 314 ofdisplaying an image of the tool clamping the tissue on the userinterface display, a step 316 of energizing the motor, in response to auser command to cut tissue, so as to move the knife from a pre-cutposition to a cut-complete position to cut the tissue, and a step 318 ofsuperimposing an indicator of knife position on the user interfacedisplay, during and/or after cutting of the clamped tissue.

Preferred embodiments of this invention have been described herein,including the best mode known to the inventors for carrying out theinvention. Variations of those preferred embodiments may become apparentto those of ordinary skill in the art upon reading the foregoingdescription. The inventors expect skilled artisans to employ suchvariations as appropriate, and the inventors intend for the invention tobe practiced otherwise than as specifically described herein.Accordingly, this invention includes all modifications, alternativeconstructions and equivalents of the subject matter recited in theclaims appended hereto as permitted by applicable law. Moreover, anycombination of the above-described elements in all possible variationsthereof is encompassed by the invention unless otherwise indicatedherein or otherwise clearly contradicted by context.

What is claimed is:
 1. A system comprising: an end effector having a jawfor clamping a material and a cutting element within the end effector;and a processor; wherein: the cutting element is moveable relative tothe end effector; the cutting element is driven by a drive element and amechanism coupling the drive element to the cutting element; and theprocessor is configured to: determine a position of the cutting elementrelative to the end effector via a displacement of the drive element anda displacement of the mechanism; and display, on a user interface, anindicator of the position of the cutting element relative to the endeffector.
 2. The system of claim 1, wherein the processor is furtherconfigured to display a video image showing at least a portion of anenvironment of the end effector.
 3. The system of claim 2, wherein theindicator is superimposed on the video image.
 4. The system of claim 3,wherein the indicator comprises a synthetic representation of thecutting element.
 5. The system of claim 1, wherein to display theindicator, the processor is configured to display the indicator inresponse to a trigger condition.
 6. The system of claim 5, wherein thetrigger condition comprises the cutting element stopping at anintermediate position during a movement between a pre-cut position and acut-complete position.
 7. The system of claim 1, wherein the indicatorof the position of the cutting element shows at least one of a locationof the cutting element or an orientation of the cutting element.
 8. Thesystem of claim 1, wherein the processor is further configured todisplay a second indicator of an orientation of the cutting element. 9.The system of claim 1, wherein the cutting element is rotated to extendbeyond a grasping surface of the jaw when the cutting element is betweena pre-cut position and a cut-complete position.
 10. The system of claim1, wherein the processor is further configured to update the display ofthe indicator in real time.
 11. A method comprising: determining, by aprocessor, a position of a cutting element relative to an end effectorvia a displacement of a drive element and a displacement of a mechanism,the end effector having a jaw for clamping a material, the cuttingelement being located within the end effector and being moveablerelative to the end effector, the cutting element being driven by adrive element and a mechanism coupling the drive element to the cuttingelement; and displaying, on a user interface, an indicator of theposition of the cutting element relative to the end effector.
 12. Themethod of claim 11, further comprising displaying a video image showingat least a portion of an environment of the end effector.
 13. The methodof claim 12, further comprising superimposing the indicator on the videoimage.
 14. The method of claim 13, wherein the indicator comprises asynthetic representation of the cutting element.
 15. The method of claim11, wherein displaying the indicator comprises displaying the indicatorin response to a trigger condition.
 16. The method of claim 15, whereinthe trigger condition comprises the cutting element stopping at anintermediate position during a movement between a pre-cut position and acut-complete position.
 17. The method of claim 11, wherein the indicatorof the position of the cutting element shows at least one of a locationof the cutting element or an orientation of the cutting element.
 18. Themethod of claim 11, further comprising displaying a second indicator ofan orientation of the cutting element.
 19. The method of claim 11,wherein the cutting element is rotated to extend beyond a graspingsurface of the jaw when the cutting element is between a pre-cutposition and a cut-complete position.
 20. The method of claim 11,further comprising updating the display of the indicator in real time.